I. Field of the Invention
The present invention relates generally to internal combustion engines and, more particularly, to such an engine which utilizes a rotor to rotatably drive an engine drive shaft.
II. Description of the Prior Art
There are a plurality of previously known internal combustion engines. Many of these previously known engines, for example conventional gasoline and diesel engines, utilize a plurality of pistons reciprocably disposed in cylinders and secured at one end to a crankshaft.
A still further type of internal combustion engine is a Wankel engine. The Wankel engine, in its most common form, comprises a triangular lobe which rotates both with respect to the drive shaft and with respect to the engine block or housing.
A still further type of internal combustion engine is a rotor driven or rotary engine. This type of engine, which is modelled after a hydraulic motor, comprises a rotor secured to a drive shaft and is rotatable within an elliptical chamber. A plurality of vane members are circumferentially equidistantly spaced around the rotor and are radially slidable within the rotor. The vane members in combination with the elliptical chamber and the rotor form a plurality of separated chambers into which a fuel/air mixture is compressed and ignited to rotatably drive the rotor, and hence the drive shaft.
These previously known rotary engines, however, have not enjoyed widespread commercial success for a number of reasons. One difficulty with these previously known rotary engines is that such engines have been quite inefficient. This disability has thus rendered the rotary engine unacceptable for a wide variety of internal combustion engine applications.
A still further disadvantage of these previously known rotary engines is that due to the relatively large number of engine combustions per revolution of the drive shaft, such engines tend to rapidly overheat. Conventional engine cooling systems have proven inadequate to cool these previously known rotary engines and more efficient and complex cooling systems were deemed impractical due to the prohibitive cost involved.
Also, in previously known rotary engines utilizing vane members to separate the chambers, rather expensive and complicated means have been employed to urge the vanes into sealing contact with the wall defining the combustion chamber.